Automatic electric block-signal.



PATENTED JUNE 28, 1904.

w. A. LUBY. AUTOMATIC ELECTRIC BLOCK SIGNAL.

' APPLICATION FILED mm 25.1903.

N0 MODEL Patented June 28, 1904.

PATENT EETCE.

TILLIAM A. LUBY, OF KALAMAZOO, MICHIGAN.

AUTOMATIC ELECTRIC BLOCK-SIGNAL- SPECIFICATION forming part of Letters Patent N 0. 763,41 1, dated June 28, 1904.

Application filed June 25, 1903.

To (all whom it may concern;

Be it known that 1, WILLIAM A. LUBY, a citizen of the United States, residing at the city of Kalamazoo, in the county of Kalamazoo and State of Michigan, have invented a new and useful Improvement in Automatic Electric Block-Signals, of which the following is a specification.

My invention relates to and has for its object a system of automatic electric block-signals for single-track railroads that will perform the functions usual to double-track systems and in which one signal placed at the abutting ends of two blocks performs functions for each block. The system is designed to be operated by either a continuous current from local batteries or from a common source and also with an alternating current from a common source. When local batteries are used, no wires are required along the track, the rails being the only circuit-conductors from one end of a block to the other.

The means by which I accomplish my object is illustrated in the accompanying draw: ings, which form a part hereof, and in which like letters and figures of reference refer to similar parts throughout the several views.

Figure 1 is a diagrammatic illustration showing one full and two partial blocks. Fig. 2"

is a similar View of the rail-circuit illustrated in Fig. l, the rails being reversed in drawing the diagram to avoid crossing of wires. This reversal, however, follows the consecutive tracing of the circuit. Fig. 3 is a diagram matic illustration showing a modification of the arrangement illustrated in Fig. 1 in which the coil of magnet E is substituted for the resistance K, which is omitted. Fig. 4: is a similar illustration in which is shown the rail-circuit illustrated in Fig. 3, its arrangement and object being the same as that of Fig. 2. Fig. 5 is also a diagrammatic illustration of a modification in which the terminals of coil 0 are directly connected to the track-rails, resistance K, coil F, and interrupter M being omitted.

The signal used at the abutting ends of two blocks to do service for each stands normally at danger by gravity and is controlled by a normally open local signal-circuit the interrupter of which is actuated by a difl'erential Serial No- 163,044. (No model.)

electromagnet which is controlled by the normally closed rail-circuits of abutting blocks.

abutting block, as shown in Figs. 1, 2, 3, 4L.

The reason of this preference rests in the fact that any variation in the source of energy will affect both coils alike. It will thus be seen that the coils of the differential magnet may be connected in different ways so as to be under the control of the rail-circuits of abutting blocks without departing from the spirit of my invention. Coils C and D have the same ampere-turns. They are connected in circuit so that the current passesthrough them in opposite directions in order that the magnetismof one coil may neutralize that of the other. The differential magnet G D may be of any suitable design, the solenoid form being used in some of the figures more to "facilitate an open illustration than to indicate a preference. In its normal condition a current is constantly flowing through the rail-circuit, as follows: from source a through wire 9 to po1nt3,

where it divides into two portions, one portion flowing through wire a, 0011 E, WIIGO,

rail B wire s, 0011 F, wlre Q, rail A and w re 3"? p to point 4. The other portion flows from i point 3 through interrupter L, contact-point? and wire 0, coil D, and wire Z to point 4',

where the two portions unite and flow through wire 29 from point 4 to point. 1 where the current again divides into two portions, one portion flowing through resistance K to point m, the other portion flowing through. wire Zc, coil 0, wire 7" and contact-point, interrupter M, and wire c" to pointrc, where the two portions again unite and flow through wire 7) to the source of energy a, completing the circuit. The portions into which the current of the circuit divides may or may not be equal. In the present circuit it is preferred to have it divide into practically equal portions, since coils F and D have substantially the same work to perform. Since asmall leakage will take place across the rails A and B, however, it is preferred to make the portion which flows through these rails enough greater to be equal to that of the other branch of the circuit when the leakage is deducted. In whatever manner these portions are arranged the resistance K should be such as to allow coil C to get the same ampere-turns as D gets.

I is an ordinary alternating-current transformer, the terminals of the primary coil being connected to the power-circuit .2 2, which is energized by an alternator Q. The terminals of the secondary coil (1 are connect ed to the rail-circuit and those of secondary coil 0 to the signal-circuit. It will be understood that the signal and rail circuits may be energized in any suitable manner or by any suitable current.

Assuming a train to have entered block N, its wheels and axles form a path of very low resistance across the track-rails A and B and short-circuit the parallel coil D, as hereinafter described with reference to coil 1). Coil 0 now becomes active, if block O is safe, and draws down plunger R, which is connected by a suitable cord or link w to interrupter J. The downward movement of plunger R actuates interrupter J and brings it into contact with pointf. The signal-circuit being thus closed, a current flows from the source of energy 0 through wire (Z, coil Ur, wire m, interrupter J, pointf', and wire 0 to the source of energy 0, completing the circuit. Coil G being energized, it draws down its plunger a, which is attached by a suitable rod or cable 2; to signal H in such a way that the downward movement of the plunger draws the signal to an inclined position indicating safety. If block 0 is not safe at the time the train enters block N, 00110 will be demagnetized and the signal-circuit will remain open, there being no current in either coil D or coil G to affect plungerR. When the train passes from block N into block 0, its wheels and axles form a path of low electrical resistance across rails A and B, thereby short-circuiting magnet F, when the counterweight S causes interrupter M to break electrical contact with stop f, which opens the circuit through coil C. There being now no pull on plunger R, interrupter J moves by gravity from stop f, opening the signal-circuit, and signal H moves by gravity back to the position of danger. The movement of interrupter J in opening the signal-circuit draws plunger R upward to its normal position. When the whole of the train has passed from block N into block 0, the circuit from the source of energy a will againflow through coil D, and coil C being now deenergized coil D will be active and will draw down plunger R, close the signal-circuit, and again bring signal H to the position of safety, as

described, if nothing in the meantime has disturbed the normal condition of the circuit through rails A and B. Should anything have happened, however, that prevents coil D becoming active, signal H will continue in the position of danger. The object in havingsignal H move from the position of safety to that of danger when the train is passing from block N onto block O is to inform the engineer that the signal is in proper working order, and the object in having the signal return again to the position of safety when the whole of the train has moved from block N onto block 0 is to inform the, engineer that block N is clear and safe for him to return onto, if he so desires. I am not aware of any system of automatic block-signaling in which the block-signal will allow an engineer to move his train back onto a block which he has left. Such a movement of a train is often of the greatest importance, and in so far as the same is prevented to that extent the automatic signal impedes traffic. The action of the signal just described gives a train the same freedom of movement in either direction which it would enjoy were no automatic signals used. The block-signal herein employed performs like functions for each abutting block and is always a signal to a train that may approach it from either direction, whether the movement of the train is backward or forward. Although signal H resumes the position of safety when the whole of the train has passed from block N onto block 0, if another train were now to follow on block N signal H would assume the position of danger the instant the first pair of wheels entered block N, in which position the signal would indicate to the engineer of the first train now on block 0 that i he could not return onto block N, as the same had become occupied or otherwise dangeous since he left it, and to the second train the signal would indicate that block 0 was occupied or dangerous. The operation of the circuit through rails A and B by means of which signal H has been thus brought to dangerby the second train is the same as that already described by means of which coil D was shortcireuited and signal H was brought to safety by the first train when it entered block N. When the first train was on block N, its wheels and axles bridging rails A and B short-circuited coil D. At this time block 0 was clear, coil F was energized, and the circuit was maintained through coil (1, which coil operated plunger R, causing H to come to safety. When the whole of the first train has passed from block N onto block 0, coil F is shortcircuited and coil C deenergized by the interruption of the circuit through it. The wheels and axles of the first train no longer bridging rails A and B, coil D ceases to be short-circuite'd and becoming active operates plunger R, causing signal H to again come to safety. Now while the first train is entirely in block O,short-circuiting coil F and causing the circuit through coil C to be interrupted, signal H will be at safety so long as coil D is active. The second train, however, on entering block N short-circuits coil D in exactly the same manner as did the first train. Coil G being dcenergized,the short-circuiting of coil D by the second train causes that coil to release attraction on plunger R, when interrupter J, moving by gravity, opens the signal-circuit and allows signal H to come to danger by gravity. WVhen the first train was on block N, short-circuiting coil D, it was the action of coil G which caused signal H to come to safety. When that train entered entirely upon block 0, it was the action of coil D which caused signal H to come to safety. The condition of the circuits through coils C and D when the first train occupied block 0 and the second enters block N is precisely the same as that which existed when the first train was partly on each block. The train being now on block 0, the same action takes place with reference to signal H as already described with reference to signal H when the train was on block l. The wheels and axles of the train bridging rails A and B form an electric path of very low resistance and the current will flow from source of energy a through wires g n, coil E, wirer, rail B, the wheels and axles of the train, rail .A, and wire 1) to point 1 where it divides into two portions if block P is safe, one portion flowing from point 9 through wire 7t, coil 0, wire y", stop and interrupter M, and wire t" to point no. The other portion flows through resistance K to point m. If block P is not safe, coil F will be deenergized, either from a short circuit or an interruption of the current through it, and interrupter M will have broken the circuit through coil C, in which case the current will not divide at point y but will flow as a unit through resistance K to point in, from which point it flows as a unit through wire it to the source of energy (1., completing the circuit. A very small portion of current will also flow from point 3through interrupter L, stop and wire 0, coil D, and wire Z to point 4. The current that will so flow through this parallel shunt, however, is negligible and is so considered throughout this specification wherever coil D D is referred to as being short-circuited. The reason that the current which flows through this parallel branch of the circuit is so small as to be negligible is due to the the fact that coil EE is of very low resistance, preferably not higher than one one-hundredth part of one ohm, thong-hit may practically be as low as the one two-hundredth part of one ohm, (equivalent to the resistance of about two feet of N o. 14 copper wire,) while the resistance of coil D D will be preferably not lower than one ohm. WVith such resistances the current that will flow through the parallel branch when a train bridges the rails of a block will current.

be about one two-hundredth part of the whole The difference between the resistances of these coils may be very much less than that mentioned, interrupter M being adjusted so as not to respond to the magnet when rails A and B are occupied by a train. Under the circumstances stated of block P being safe coil D being deenergized by the train on block 0 coil C becomes active, draws down plunger R, causing interrupter J to close the signal-circuit, when coil G becomes active and draws down signal H to the position of safety. If block P be safe at the time the train enters blockO from block N, signal H will at that time come to the position of safety. If block P be not at that time safe, signal H will remain in the position of danger until block P becomes safe, when it will assume the position of safety and there continue until block P becomes dangerous. As the train on block 0 enters block P the wheels and axles of thetrain form a path of low resistance across rails A and B short-circuiting the current from coil F, the deenergizing of which allows interrupter M to open the circuit through coil C by gravity. As a portion of the train is now on block P and another portion of it on block 0, coils C and D are both denergizedcoil C by the interruption of currentthrough it and coil D by being short-circuited. There now being no attraction on plunger R, interrupter J moves by gravity and opens the signal-circuit, thereby deenergizing coil G and allowing signal H to move by gravity to the position of danger. When the whole of the train has passed from block 0 onto block P, the current from source a will flow normally through coil D, energizing it and causing it to actuate plunger R. The downward movement of plunger R operates interrupter J, which closes the signal-circuit, when coil G becomes energizcdand draws signal H again to the position of safety. Should a rail break in block 0, the circuit will be interrupted through coils E, C, D, and Y F. Were Wire 0 connected directly to wire g at point 3, the breaking of a rail would not. deenergize coil D and a train on block P approaching block 0 would find signal H indicating safety when the block was dangerous from a broken rail. It is to avoid suchafalse signal that interrupter L is used. l/Vhen the rail breaks, the current is interrupted through coil E, the attraction ceases, and interrupter L, moved by gravity, opens the circuit through coil D. When the circuit is again established through coil E by the repair of the broken rail, interrupter L is again attracted and again makes the circuit through coil D. A train on block P moving toward signal H could not get a safety-signal, since coil D is not active. If a train were on block N mov ing toward signal H, that signal would stand at danger, since suchv train would shortcircuit coil D, as described, and coil C would be denergized by the interruption of the current through coil F. If a train were on block P, coil F will be deenergized and the circuit through coil C will be broken, and if block 0 is clear coil D will actuate interrupter J, closing the signal-circuit and causing signal H to come to "safety. \Vhen the train moves from block P onto block C, its first pair of wheels will short-circuit coil D and interrupter J will open the signal-circuit. Coil G becoming deenergized, signal H will resume its normal position of danger by gravity. When the whole of the train shall have passed from block P onto block 0, coil F will again become active, since it is no longer short-circuited, interrupter M will close the circuit through coil C, and this coil will actuate interrupterJ, bringing signal H to safety if block P has not become d'angerous. The train now being entirely on block 0, the operation of signals H and II will be the same as that already described when the train entered block 0 from block N. It should be noticed that from whatever direction atrain enters block 0 (which is true of all blocks) coils F and D will be short-circuited.

In the modification shown in Figs. 3 and t the resistance K is omitted and coil E is connected in its place. This change does not change the working of the signals of a block from that already described. The current that energizes the rail-circuit, however, is differently divided. Commencing with the source of energy a the current flows through wire g to point 3, where it divides into two portions, one portion flowing through wire a 0', rail B, wire s, coil F, wire q, rail A, and wire j) to point 9 where it divides into two portions, one portion flowing through coil E to point in, the other portion flowing through coil C, wire and stop 1', interrupter M, and wire v." to point an. The second portion of the original division flows from point 3 through interrupter L, wire 0, coil D, and wire Z to point 00, where the different divisions unite and flow through wire 72/ to the source of energy, completing the circuit. The resistances of the various branches of this circuit are to be proportioned and arranged according to Chms law, so as to give coils C and D the same ampere-turns.

In the modification shown in Fig. 5 coils C and D are energized by different sources of energy, C being energized by the source of energy a and D by the source of energy a. Commencing with the source of energy (1 the current flows through wire to point 3,where it divides into two portions, as did that of the other modifications, one of the portions flowing through wire 0/, coil E, wire a", rail B, wire s, coil C, wire 9, rail A, and wire 7) to point 4.. The other portion flows through interrupter L, stop and wire a, coil D, and wire 6 to point 4, where both portions unite and flow through wire 71/ to the source of energy a, completing the circuit. It will be noticed that this circuit is precisely like that illustrated in Figs. 1 and 2, except that when the two portions of the current unite at point 4 they do not again divide before completing the circuit, there being no occasion for a second division, since coil C is not energized by the source of energy (1.". Coils C and D have the same ampere-turns and are wound and connected, as before stated, so that the current flows through them in opposite directions. A train on block N short circuits coil D, and coil C if block O is clear becomes active and actuates interrupter J, as heretofore described. \Vhen the train passes from block N onto block 0, coil C is short-circuited, as was coil F, and coil D actuates interrupter J.

It will be understood that all the coils used in the rail-circuit should be of low electrical resistance, according to the practice in block signaling, to minimize the leakage of current across the rails.

In connecting the rail-circuit (illustrated in Figs. 3 and 4:) care must be taken to connect one terminal of the parallel branch (the branch which includes coil D and interrupter L) at a point between the source of energy and coil E, for if it were connected between coil E and rail A a broken rail would not be properly indicated.

By the term a series shunt as herein employed I mean a shunt of the rail-circuit which is in series with the trackrails-that is, a shunt of such a nature that a train on the block short-circuiting the rails will not. divert or lessen the current through such shunt. By the phrase a parallel shunt I mean a shunt of the rail-circuit which is in parallel with the track-rails that is, a shunt from which the current will be diverted, or in which the current will be lessened by a short-circuit bridge, such as a pair of wheels and axle across the track-rails.

Having now described my invention, What I claim as new is- 1. The combination of a signal-circuit having a source of electric energy, an electromagnet and, a circuit-interrupter; a differential electromagnet arranged to actuate said interrupter; and the track-circuits of two abutting signaling-blocks for controlling said differential magnet.

2. The combination of a signal; asignal-circuit having a source of electric energy, an electromagnetic device for actuating said signal and a circuit-interrupter; a differential electromagnet arranged to actuate said circuit-interrupter included in said signal-circuit; and the track-circuits of two abutting signalingblocks for controlling said differential magnet.

3. The combination of a signal-circuit having a source of electric energy, an electromagnet and. a circuit-interrupter; a differential elcctromagnet arranged to actuate said circuitinterrupter; and the rail-circuits of two abutting signaling-blocks, one of said rail-circuits having a parallel shunt including one of the coils of said differential magnet, and also a series shunt including a circuit-interrupter and the other coil of said differential magnet, the other of said rail-circuits having an electromagnet arranged to control the circuit-interrupter included in said series shunt.

L. The combination of a signal-circuit hav-' ing a source of electric energy, an electromagnet and a circuit-interrupter; a differential electromagnet arranged to actuate said circuitinterrupter; and the rail-circuits of two abut' ting signaling-blocks, one of said rail-circuits having a parallel shunt including one of the coils of said differential magnet and also a series shunt including a circuit-interrupter, and the other coil of said differential magnet, the various parts of said circuit being so arranged and the resistances so proportioned that each of the differential coils will be energized by equal ampere-turns, the other of said rail-circuits having an electromagnet arranged to control the circuit-interrupter included in said series shunt.

5. The combination of a signal-circuit having a source of electric energy, an electromagnet and a circuit-interrupter; a differential electromagnet arranged to actuate the circuitinterrupter included in said signal-circuit; and the rail-circuits of two abutting signalingblocks, one of said rail-circuits having a parallel shunt including one of the coils of said differential magnet, and also having two series shunts, one of said series shunts including a circuit-interrupter and the other coil of said differential magnet, the other series shunt including an electrical resistance adapted to regulate the current that flows through the differential coil in said first-mentioned series shunt, the other of said rail-circuits having an electromagnet arranged to actuate the circuit-interrupter included in the series shunt of the first-mentioned rail-circuit.

6. The combination of a signal-circuit having a source of electric energy, an electromagnet and a circuit-interrupter; a differential electromagnet arranged to actuate the circuitinterrupter included in said signal-circuit; and the rail-circuits of two abutting signalingblocks, one of said rail-circuits having a parallel shunt including a circuit-interrupter and one of the coils of said differential magnet, an electromagnet connected in series with one of the track-rails and arranged to actuate the circuit-interrupter included in said parallel shunt, and also having two series shunts, one of said series shunts including a circuit-interrupter and the other coil of said differential magnet, the others series shunt including an electrical resistance adapted to regulate the current that flows through the differential coil in said first-mentioned series shunt, the other of said rail-circuits having an electromagnet arranged to actuate the circuit-interrupter included in the series shunt of the firstcuit; and the rail-circuits of two abutting signaling-blocks, one of said rail-circuits having a parallel shunt including one of the coils of said differential magnet, and also having two series shunts, one of said series shunts including a circuit-interrupter and the other coil of said differential magnet, the other series shunt including an electrical resistance adapted to regulate the current that flows through the differential coil in said first-mentioned series shunt, the other of said rail-circuits having an electromagnet arranged to control the circuit-interrupter included in the series shunt of the first-mentioned rail-circuit.

8. The combination of a signal; a signal-circuit having asource of electric energy, an electromagnet and a circuit-interrupter; a differential electromagnet arranged to actuate the circuit-interrupter included in said signal-circuit; and the rail-circuits of two-abutting signaling-blocks, one of said rail-circuits having a parallel shunt including a circuit-interrupter and one of the coils of said differential magnet, an electromagnet connected in series with one of the track-rails and arranged to actuate the circuit-interrupter included in said parallel shunt, and also having two series shunts, one of said series shunts including a circuit-interrupter and the other coil of said diflerential magnet, the other series shuntincluding an electrical resistance adapted to regulate the current that flows through the differential coil in said first-mentioned series shunt, the other of said rail-circuits having an electromagnet arranged to actuate the circuit-interrupter included in the series shunt of the first-mentioned rail-circuit.

9. In a rail-circuit, the combination of a source of electric energy, the rails of a signaling-block, the coils of three electromagnets and a circuit-interrupter, one of said coils having itsterrninals connected to the trackrails at one end of the signaling-block, the other coils, said source of energy and the circuit-interrupter being located at the opposite end of said signaling-block, one of the coils located at the end of the block where said source of energy is situated having its terminals connected in a parallel shunt, the circuitinterrupter and the other coil located at the end of the block where the source of energy is situated being connected in a series shunt, the said circuit-interrupter being arranged to make and break the circuit through the coil so connected in said series shunt.

- 10. In a rail-circuit, the combination of a source of electric energy, the rails of a sig- IIO naling-block, the coils of three electromagnets, a circuit-interrupter and an electrical resistance, one of said coils having its terminals connected to the track-rails at one end of said block, the other coils, said source of energy, said circuit-interrupter and said electrical resistance being located at the opposite end of said block, one of the coils located at the end of the block Where said source'of energy is situated having its terminals connected in a parallel shunt, the circuit-interrupter and the other coil located at the end of the block where said source of energy is situated being connected in a series shunt, the said circuitinterrupter being arranged to make and break the circuit through the coil so connected in said series shunt, and the said electrical resistance being connected in an independent series shunt and adapted to regulate the proportion of current that flows through the coil so connected in series shunt.

11. In a rail-circuit, the combination of a source of electrical energy, the rails of a signaling-block, the coils of four electromagnets, two circuit-interrupters and an electrical resistance, one of said coils having its terminals connected to the track-rails at one end of said block, the other coil, said source of energy, said eircuit-interrupters and said electrical resistance being located at the opposite end of said block, one of the coils located at the end of the block Where said source of energy is situated and one of the circuit-interrupters being connected in a parallel shunt, the circuit-interrupter so connected in said parallel shunt being arranged to make and break the circuit through the coil so connected in said parallel shunt, one of the coils located at the end of the block Where the source of energy is situated being connected in series with one of the track-rails and arranged to actuate the circuitinte1"ru1i ter connected in said parallel shunt, the other coil located at the end. of the block Where said source of energy is situated and the other circuit-interrupter being connected in a series shunt, the circuit-interrupter so connected in said series shunt being arranged to make and break the circuit through the coil so connected in said series shunt, and the said electrical resistance being connected in an independent series shunt and adapted to regulate the proportion of current Which flows through the coil so connected WVitnesses:

G. N. BURKE, SAMUEL W. OuuNFoRD. 

